Capacitors continue to have increasing aspect ratios in higher generation integrated circuitry fabrication. For example, dynamic random access memory (DRAM) capacitors may have elevations of from about 2 to about 3 microns, and widths of about 0.1 micron. Further, it is a continuing goal to increase the density of semiconductor devices, with a corresponding goal to reduce the footprint associated with individual devices.
It can be difficult to fabricate and utilize the tall, thin capacitors of high-density integrated circuitry in that such capacitors may be structurally weak and subject to toppling or breaking from an underlying base. Accordingly, lattices have been developed to support capacitor electrodes. However, difficulties continue to be encountered as capacitor electrodes become increasingly more tightly packed. An example difficulty is described with reference to FIGS. 1-3.
FIG. 1 shows a semiconductor construction 10 comprising a base 12. The base comprises a semiconductor substrate 11 supporting a pair of electrodes 14 and 16. Container-shaped capacitor storage node structures 18 and 20 are supported over the electrodes, with such storage node structures comprising electrically conductive material 22. The storage node structures are formed within openings that extend through a sacrificial material 24. A lattice structure 26, comprising electrically insulative material 28, is adjacent the storage nodes. The lattice structure will provide support to the storage nodes after the sacrificial material 24 is removed.
FIG. 2 shows a desired configuration resulting from removal of sacrificial material 24 (FIG. 1), and FIG. 3 shows a problematic configuration that can occur instead of the desired configuration. Specifically, in some applications segments of adjacent storage nodes may be drawn together during the removal of sacrificial material 24 (FIG. 1) to cause a short 30 between the adjacent storage nodes. One mechanism by which the adjacent segments may be drawn together to form short 30 is the generation of capillary forces between the adjacent segments during wet etching of the sacrificial material 24 (FIG. 1).
It is desired to develop new methods of fabricating capacitors which alleviate or prevent the problem shown in FIG. 3. It is further desired for such methods to be suitable for other applications besides fabrication of the particular capacitor storage nodes of FIGS. 1-3. It is also desired to develop new structures, such as capacitor constructions, through such methods.